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McNaughton D, Robertson EG, Thompson CD, Chimdi T, Bane MK, Appadoo D. Overview of High-Resolution Infrared Measurement and Analysis for Atmospheric Monitoring of Halocarbons. Anal Chem 2010; 82:7958-64. [DOI: 10.1021/ac101425d] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Don McNaughton
- School of Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800, Australia, La Trobe University, Department of Chemistry, Bundoora, Victoria 3086, Australia, and Australian Synchrotron, Blackburn Road, Clayton, Victoria 3168, Australia
| | - Evan G. Robertson
- School of Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800, Australia, La Trobe University, Department of Chemistry, Bundoora, Victoria 3086, Australia, and Australian Synchrotron, Blackburn Road, Clayton, Victoria 3168, Australia
| | - Christopher D. Thompson
- School of Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800, Australia, La Trobe University, Department of Chemistry, Bundoora, Victoria 3086, Australia, and Australian Synchrotron, Blackburn Road, Clayton, Victoria 3168, Australia
| | - Tarekegn Chimdi
- School of Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800, Australia, La Trobe University, Department of Chemistry, Bundoora, Victoria 3086, Australia, and Australian Synchrotron, Blackburn Road, Clayton, Victoria 3168, Australia
| | - Michael K. Bane
- School of Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800, Australia, La Trobe University, Department of Chemistry, Bundoora, Victoria 3086, Australia, and Australian Synchrotron, Blackburn Road, Clayton, Victoria 3168, Australia
| | - Dominique Appadoo
- School of Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800, Australia, La Trobe University, Department of Chemistry, Bundoora, Victoria 3086, Australia, and Australian Synchrotron, Blackburn Road, Clayton, Victoria 3168, Australia
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He Y, Müller HB, Quack M, Suhm MA. High Resolution FTIR and Diode Laser Supersonic Jet Spectroscopy of the N = 2 HF Stretching Polyad in (HF)2 and (HFDF): Hydrogen Bond Switching and Predissociation Dynamics. ACTA ACUST UNITED AC 2009. [DOI: 10.1524/zpch.2007.221.11-12.1581] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We report Fourier transform infrared (FTIR) and high resolution diode laser spectra (∼ 1MHz instrumental bandwidth) obtained in cooled absorption cells as well as in a supersonic jet expansion for the N = 2 polyad region of the HF-stretching vibrations of (HF)2, HFDF and DFHF. Three vibrational transitions have been observed for (HF)2 and two for both monodeuterated isotopomers. For (HF)2 we have identified and analysed the observed transitions of the polyad member 22 of the type Δ K
a = 0 and Δ K
a = ± 1 up to rotational sublevel Δ K
a = 3. Band centers as well as rotational constants of all four K
a states have been determined. The tunneling splittings due to hydrogen bond switching for these four K
a states have been investigated, with the Δ K
a = 0 up to Δ K
a = 2 sublevels having tunneling symmetry Γ
vt = A
+ for the lower tunneling states, and switching periods ranging from 158ps for K
a = 0 to 1.35ns for K
a = 2. A tunneling level inversion is found at Δ K
a = 3, leading to a symmetry Γ
vt = B
+ for the lower tunneling state of this K
a-sublevel. The vibrational assignment of the measured spectra of (HF)2 was established by comparison with the monodeuterated isotopomers HFDF and DFHF. For HFDF we have identified and analysed five subbands between 7600cm-1 and 7730cm-1. We have determined the spectroscopic constants of the rotational levels Δ K
a = 0 and Δ K
a = 1 for the vibrationally excited state and of the levels of Δ K
a = 1 and Δ K
a = 2 of the ground state, the latter from combination differences. From the measurements in a supersonic jet expansion we determined the predissociation line width of the N = 22, K
a = 1 to be about 120MHz for the Γ
vt = A
+ tunneling state of (HF)2 and about 90MHz for Γ
vt = B
+. For the Δ K
a = 0 level of N = 22 we obtained predissociation line widths ranging around 100MHz, similar to those of the Δ K
a = 1 level. In the case of HFDF, the predissociation line width of Δ K
a = 1 is about 80MHz. Predissociation lifetimes for these levels with the unbonded HF stretching excited thus are in the range of about 1 to 2ns. The predissociation width in the N = 21 level is uncertain by about a factor three with lg(Δν/MHz) = (3 ± 0.5) and in N = 23 it is about 600MHz corresponding to rounded lifetimes of 0.1ns and 0.3ns when the bonded HF stretching is excited thereby demonstrating strongly mode selective predissociation rates in the N = 2 polyad. Under thermal equilibrium conditions we derived the pressure broadening coefficient for (HF)2 (γ = (6 ± 1) × 10-4cm-1/mbar in the wavenumber range between 7713cm-1 and 7721cm-1 for total gas pressures between 10 and 60mbar, all values as full widths half maximum). For absolute frequency calibrations we have remeasured the first overtone transitions of the monomer HF with much improved precision between P(5) (7515.80151cm-1) and R(7) (7966.22188cm-1).
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Hippler M, Oeltjen L, Quack M. High-Resolution Continuous-Wave-Diode Laser Cavity Ring-Down Spectroscopy of the Hydrogen Fluoride Dimer in a Pulsed Slit Jet Expansion: Two Components of the N = 2 Triad near 1.3 μm. J Phys Chem A 2007; 111:12659-68. [DOI: 10.1021/jp076894s] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael Hippler
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland, and Department of Chemistry, University of Sheffield, Sheffield S3 7HF, England
| | - Lars Oeltjen
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland, and Department of Chemistry, University of Sheffield, Sheffield S3 7HF, England
| | - Martin Quack
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland, and Department of Chemistry, University of Sheffield, Sheffield S3 7HF, England
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Chung S, Hippler M. Infrared spectroscopy of hydrogen-bonded CHCl3-SO2 in the gas phase. J Chem Phys 2007; 124:214316. [PMID: 16774416 DOI: 10.1063/1.2207617] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A molecular association between chloroform and sulfur dioxide in the gas phase at room temperature was studied by Fourier transform infrared spectroscopy. Since the intensity of the CH-stretching fundamental vibration of monomer chloroform is very weak but much stronger upon complexation, a simple subtraction procedure isolated the CH-stretching vibration spectrum of the complex. The presence of a 1:1 complex was confirmed by two dilution series, where the monomer concentrations were varied. The molecular association manifested itself as a shift of the peak absorbance of the CH-stretching vibration of CHCl3-SO2 by +7 cm(-1) and of the CD-stretching vibration of CDCl3-SO2 by +5 cm(-1) to higher wave numbers compared to monomer chloroform, accompanied by a considerable broadening of the band contour. In agreement with previous ab initio calculations, this indicates a "blueshifting" or more appropriately, a "C-H contracting" hydrogen bond between chloroform and sulfur dioxide. An estimate of the complex concentration was made based on ab initio calculations for the integrated band strength and the measured spectrum. With this estimate, the equilibrium constant Kp (295 K)=0.014 (po=10(5) Pa) for the dimerization was calculated, providing one of the very few cases where the formation of a hydrogen-bonded gas phase complex at room temperature could be quantitatively studied by infrared spectroscopy.
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Affiliation(s)
- Susan Chung
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
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Ito F, Hirabayashi S. Infrared spectra of the CF3I dimer: A concurrent application of matrix-isolation spectroscopy and cavity ring-down spectroscopy. J Chem Phys 2006; 124:234509. [PMID: 16821931 DOI: 10.1063/1.2206784] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We have observed infrared spectra of the CF(3)I dimer produced in a supersonic jet by matrix-isolation Fourier transform infrared spectroscopy and infrared cavity ring-down (IR-CRD) spectroscopy. In the matrix-isolation experiments, the dimer was isolated in an Ar matrix by the pulse-deposition method. The recorded spectral range covers the symmetric (nu(1)) and doubly degenerate (nu(4)) C-F stretching regions. From the concentration dependence of the matrix-isolation spectra we have assigned one dimer band for each fundamental region. It was not easy to identify the dimer band for the nu(4) band because of the multiplet feature of the monomeric nu(4) band caused by the site symmetry breaking. The spectra of (CF(3)I)(2) in the nu(4) band region were thus also measured in the gas phase by IR-CRD spectroscopy, where we detected two dimer bands. Comparing the observed band positions with the results of quantum chemical calculations, we have assigned the observed dimer bands to the head-to-head isomer. The structure of (CF(3)I)(2) and its photochemical implications are discussed, in comparison with methyl iodide dimer reported previously [Ito et al., Chem. Phys. Lett. 343, 185 (2001)].
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Affiliation(s)
- Fumiyuki Ito
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba-West, Onogawa 16-1, Tsukuba, Ibaraki 305-8569, Japan.
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Snels M, Beil A, Hollenstein H, Quack M, Schmitt U, D’Amato F. Rotational analysis of the ν1band of trichlorofluoromethane from high resolution Fourier transform and diode laser spectra of supersonic jets and isotopically enriched samples. J Chem Phys 1995. [DOI: 10.1063/1.470073] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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